Fifth Japanese power reactor restarted

12 August 2016

Shikoku Electric Power Company announced today that it had initiated the process to restart unit 3 of its Ikata nuclear power plant in Japan's Ehime prefecture. It becomes the fifth Japanese reactor to resume operation under new safety standards introduced following the March 2011 accident at the Fukushima Daiichi plant.

The company said that at 9.00am today it began the operation to extract the control rods from the reactor's core, allowing the fission process to begin.

Shikoku announced on 5 August that it planned to restart the unit today and that power generation would resume on 15 August. Output from the 846 MWe pressurized water reactor will then gradually be increased and full capacity should be reached on 22 August. The unit is set to re-enter commercial operation in early September.

Ikata 3 has been idle since being taken offline for a periodic in April 2011.

Under Japan's reactor restart process, plant operators are required to apply to the Nuclear Regulation Authority (NRA) for: permission to make changes to the reactor installation; approval of their construction plan to strengthen the plant; and, approval of the plant's operational safety programs. Operators are required to add certain safety-enhancing equipment within five years of receiving the NRA's approval of a reactor engineering work program.

Shikoku submitted its engineering work program for Ikata 3 to the NRA in July 2013. This was approved by the NRA in July last year. That approval - which means the NRA considered the reactor, and the plant as a whole, to be safe for operation - represented by far the major part of the licensing process. Shikoku's 'construction plan' for Ikata 3 - what it plans to do to strengthen the unit - was approved on 23 March this year. The utility received approval for its operational safety programs - the third and final approval - on 19 April. The NRA has since carried out final pre-operational safety inspections of the unit. The loading of fuel into Ikata 3 was then carried out 24-27 June.

Unit 1 of Kyushu Electric Power Company's Sendai plant in Kagoshima prefecture was the first to be restarted last August, followed by Sendai 2 in October. Unit 3 of Kansai Electric Power Company's Takahama nuclear power plant in Fukui prefecture resumed operation on 29 January. Takahama 4 was restarted on 26 February, but has remained offline since 29 February following an automatic shutdown of the reactor due to a "main transformer/generator internal failure". However, an injunction imposed by a district court on 9 March led to unit 3 being taken offline as well and both units have since remained idle.

Another 20 reactors are moving through the restart process, which has been prioritised to bring on the most-needed reactors first, in the localities and prefectures more supportive of restart.